Selective removal of tertiary olefines



Patented Aug. 6, 1935 snnsc'nva mover. or 'rnii'rmax onarnms Richard M.Deanealy, nanny, can. calm a Shell Development Company, San Francisco,Calif., a corporation of Delaware No 1mm; Application July 1'1, 193:,Serial No. 680,781

19 Claims.

including tertiary oleflnes, can be obtained by the pyrolytic treatmentor cracking of mineral oils as petroleum, petroleum products, coal tar,pitches, coal, peat, shale oil, and like or related carbonaceousmaterial.

If desired, the cracked stock material can be employed as mixtures ofoleflne and paraflin hydrocarbons containing varying numbers of carbonatoms per molecule or may be fractionated into suitable fractions whichpredominate in hydrocarbons containing the same number of carbon atomsto'the molecule as a butane-butene fraction, a pentane-amylene fraction,a hexanehexene fraction and the like or may comprise a plurality offractions such as a fraction consisting predominantly of hydrocarbonscontaining 4 and 5 or 5 and 6 or 4, 5 and Gcarbon atoms to the molecule.

A typical fraction would comprise the normal paraflin hydrocarbon, theiso saturated aliphatic hydrocarbon, the secondary oleflnes, thetertiary oleflne and, perhaps, small amounts of dioleflnes.

In carrying out my invention, it is desirable that moisture be absent,i. c. it is preferable to operate with substantially anhydrous reactantssince it appears that the presence of water vapor catalyses to someextent the addition reaction of hydrochloric acid to tertiary olefines.Operating with dry reactants also avoids or minimizes corrosion losses.

For example, working with a hydrocarbon mixture containing isobutylene,the following resuch as chlorine:

(1) BIG C=CHs+Cl| n ic actions are possible when resorting to halogensticularly at elevated temperatures andlor superatmospheric pressures.

Around 90%"of the theoretical yield of tertiary olefine monochloride isobtainable basedon the chlorine input. g

It is preferable, if the object is to make tertiary halo oleflnes ingood yields, to add the halogen in amount considerably less thanequivalent to the tertiary oleflne content and accept a lower yield onthe olefine base, but higher on the halogen bases.

The process can be conducted in the gaseous,

liquid or mixed gaseous-liquid phase, 1. e. a rain of hydrocarbons candescend countercurrent to ascending chlorine gas in a tower which may ormay not be packed in the conventional manner or possess plates. in thegaseous phase, can be conducted through a series of towers, where itcomes into contact with static or flowing (preferably countercurrent)liquid containing chlorine. If desired, the concentration of thechlorine in the chlorine liquid may vary with the different stages oftreatment, the initial stock material first being treated' with weakchlorine fluid and then with progressively stronger concentrations ofchlorine. Inert diluents may be incorporated with the halogen and/orreactants and oxygen may be utilized as inhibitor of the substitutionreaction of saturated organic compounds as paramn hydrocarbons and theirderivatives with halogen.

My copending applications, Serial No. 574,462 filed November 11, 1931and Serial No. 631,758 flied September 6, 1932, disclose still otherspecific methods of executing a halogenation process.

The process can be conducted in batch, intermittent or continuousfashion.

The unsaturated monochlorides can be recovered from the unattackedmaterials in various ways. If the stock material is a normally gaseousmixture, the resulting monochlorides are liquids and hence, separate outeasily. If the stock material is a normally liquid mixture, theresulting monochlorides can be recovered therefrom by extraction withsuitable solvents,- by distillation and the like.

Not only the mono-tertiary oleflnes but their homologues, the dimers,trimers, etc., as diisobutylene, ditertiary amylene and the like can behalogenated similarly. For example, diisobutylene yields monochlordiisobutylene upon chlorination which is not so readily attacked bychlorine as long as the more reactive diisobutylene is present topreferentially combine with the chlorine.

The preferential reaction may be carried out with tertiary oleflnes in amixture with one or more components as secondary oleflnes, paraffins,chlor paraflins, tertiary chlor oleflnes,.i. e.

The hydrocarbon mixture, if

unsaturated monochlorldes resulting from the chlorination of theoriginal tertiary olefines, saturatedhalogenated hydrocarbons,unsaturated halogenated hydrocarbons and the like.

The following examples are cited for exemplary purposes only and are notto be regarded in any way as limitative.

Example I and economically advantageous to make unsaturated tertiarymonohalides without first concentrating tertiary olefines in theiradmixtures with other hydrocarbons, chlor-derivatives, and the like.

A technical. pentane-amylene cut made by straight fractionation fromcracked products and having the composition:

Example II Per cent by weight Tertiary amylenes 23.8 Secondary-amylenes33.3 Pentanes 42.9

yielded the following results. Analysis of the chlorinated productsshowed that chlorine had reacted with 70% of the tertiary amylenes, 8%only of the secondary amylenes and substantially with none of thepentane. I v

Once the tertiary olefines have been removed from their admixtures, theunattacked portion is available for other reactions. The secondaryolefines present can then be halogenated with a halogenizing agent aschlorine, hydrochloric acid; or reacted with acids as phosphoric acid,sulfuric acid, the carboxylic acids, the benzene sulfonic acids andhomologues, the corresponding acid anhydrides, acid salts of polybasicmineral acids as the alkali-metal acid salts of sulfuric acid,phosphoric acid and the like, the alkyl acid esters of polybasic acidssuch as the methyl, ethyl, propyl, butyl, isobutyl, amyl, isoamyl andhigher alkyl acid esters of sulfuric and phosphoric acids; or combinedwith phenolic bodies to yield corresponding alkylated compounds, ordirectly hydrated to yield alcohols; or combined with alcohols to yieldethers, etc.

The preliminary halogenating treatment is ens-'- tomarily carried out atlow temperatures (ll-60 C.) preferably in the dark. The exact operatingtechnique is dependent on the primary objective of the operator: whetherit is desired to obtain an olefine monohalide or to selectively removetertiary olefines from hydrocarbon mixtures and the like.

The chlorinated mixture of tertiary olefines serves a useful function inthe chemical industry andmay be used per se or as andntermediate forfurther chemicals.

While I have in the foregoing described in some detail the preferredembodiment of my invention and some variants thereof, it will beunderstood that this is only for the purpose of making the inventionmore clear and that the invention is not to be regarded as limited tothe a,o1o,ssa

details of operation described, nor is it dependent upon the soundnessor accuracy of the theories which I have advanced as to the advantageousresults attained. On the other hand, the invention is to be regarded aslimited only by the terms of the claims, in which it is my intention toclaim all novelty inherent therein as broadly as is possible in view ofthe prior art.

I claim as my invention: f

1. A process for the selective halogenation of tertiary olefines intheir admixtures with compounds of the class consisting of, secondaryolefines, saturated halogenated hydrocarbons and unsaturatedhalogenated. hydrocarbons which comprises, reacting a mixture thereofwith only suflicient free halogen to efiect the substantially selectivehalogenation of the major part of the tertiary olefine present.

2. A process for the selective halogenation of tertiary olefines intheir admixtures with compounds of the class consisting of, secondaryolefines, saturated chlorinated hydrocarbons and unsaturated chlorinatedhydrocarbons which comprises, reacting a mixture thereof with onlysumcient free chlorine to efiect the substantial selective chlorinationof the tertiary olefine prescut and subsequently separating thechlorinated tertiary olefine from the unchlorinated products.

3. A process for the substantial transformation of tertiary olefines tothe corresponding unsaturated halides in the presence of secondaryolefines without substantial halogenation of the latter which comprises,reacting a mixture of secondary and tertiary olefines with substantiallynot more than the stoichiometric amount of free halogen corresponding tothe tertiary olefine content.

4. A process for the substantial transformation of tertiary olefines tothe corresponding unsaturated chlorides in the presence of secondaryolefines without substantial chlorination of the latter which comprises,reacting a mixture of secondary-and tertiary olefines with substantiallynot more than the stoichiometric amount of free chlorine correspondingto the tertiary olefine content.

5. A process for the selective halogenation of tertiary olefines in thepresence of secondary olefines and paraflin hydrocarbons withoutsubstantial halogenation of the latter which comprises, reacting amixture of paraflin hydrocarbons and secondary and tertiary olefineswith only suillcient free halogen to effect the substantially selectivehalogenation of the major part of the tertiary olefine present.

6. A process for the selective halogenation of tertiary olefines in thepresence of secondary olefines and paraifin hydrocarbons withoutsubstantial halogenation of the latter which comprises, reacting amixture of paraiiin hydrocarbons and secondary and tertiary olefineswith only sufficient free halogen to effect the substantially selectivehalogenation of the tertiary olefine present and in the presence of freeoxygen.

7. A process for the selective halogenation of tertiary olefines in thepresence of secondary olefines and paraifi'n hydrocarbons whichcomprises, reacting a mixture of parafiin hydrocarbons and secondary andtertiary olefines with only sufficient free halogen to eflfect thesubstantially selective halogenation of the tertiary olefine present,separating the halogenated tertiary oleflne from the unattacked productsand subjecting the latter to reaction with a compound capable ofcombining with a secondary oleflne.'

8. A process for the selective halogenation of tertiary olefines in thepresence of secondary olefines and paraifin hydrocarbons whichcomprises, reacting a mixture of paraflin hydrocarbons and secondary andtertiary olefines with only suflicient free halogen to effect thesubstantially selective halogenation of the major part of the tertiaryolefine present, separating the halogenated tertiary olefine from theunattached products and subjecting the latter to reaction with an acidiccompound of the class consisting of acids, acid anhydrides, acid saltsand acid esters.

9. A process for the selective chlorination of tertiary olefines in thepresence of secondary olefines and paraffin hydrocarbons whichcomprises, reacting a mixture of paraffin hydrocarbons and secondary andtertiary olefines with only suiticient free chlorine to effect thesubstantially selective chlorination of the tertiary olefine present,separating out the portion acted upon and then treating the unchangedremaining portion with a reagent capable of combining with a secondaryolefine.

10. A process for the selective chlorination of a hydrocarbon fractionconsisting predominantly of parafiin hydrocarbons and secondary andtertiary olefines of the same number of carbon atoms to the moleculewhich comprises reacting said fraction with only sufficient freechlorine to effect the substantially selective chlorination of thetertiary olefine present.

11. A process for the selective chlorination of a butane-butene reactionwhich contains butane and isomeric butenes which comprises, reactingsaid fraction with only sufiicient free chlorine to eiiect thesubstantially selective chlorination of the isobutylene present.

12. A process for the selective chlorination of a pentane-amylenefraction which contains pentane and isomeric amylenes which comprises,reacting said fraction with only suflicient free chlorine to effect thesubstantially selective chlorination of the tertiary amylene present.

13. A composition of matter essentially consisting of, a complex mixtureof mono halogenated tertiary olefines obtained by a reaction between amixture of tertiary olefines and a free halogen.

14. A composition of matter essentially consisting of, a complex mixtureof monochlor tertiary olefines obtained by reaction between a mixture oftertiary olefines and chlorine.

15. A composition of matter essentially consisting of, a complex mixtureof monochlor tertiary amylenes obtained by a reaction between a mixtureof tertiary amylenes and chlorine.

16. A process for the selective halogenation of tertiary olefines in thepresence of secondary olefines, which comprises reacting a mixture ofsecondary and tertiary olefines with only sufiicient free halogen toeffect the substantial selective halogenation of the tertiary olefinepresent while maintaining an excess of tertiary olefine.

17. A process for the selective halogenation of tertiary olefines in thepresence of secondary olefines, which comprises reacting a mixture ofsecondary and tertiary olefines with only sufilcient free halogen toeffect the substantial selective halogenation of the tertiary olefinepresent in excess in the liquid phase.

18. A process for the selective halogenation of tertiary olefines in thepresence of secondary olefines, which comprises reacting a mixture ofsecondary and tertiary olefines with only sufficient free halogen toeffect the substantial selective halogenation of the tertiary olefinepresent while maintaining an excess of tertiary olefine in the liquidphase.

19. A process for the formation. of a monohalogeno olefine from atertiary olefine, which comprises reacting an excess of the tertiaryolefine with free halogen in the presence of tertiary olefine in theliquid phase and removing the products of halogenation substantially asfast as formed.

' RICHARD M. DEANESLY.

